This invention relates to detergent compositions which are particularly suitable for use in automatic dishwashers. Such compositions are normally alkaline, contain low levels of low foaming surfactants, and contain a source of available chlorine. In order to obtain good cleaning performance, the disclosed compositions usually contain a source of alkalinity which gives a pH greater than 12 at a 1% concentration or large amounts of phosphate builders or organic builders. However, it is known that sources of alkalinity such as alkali metal metasilicates and alkali metal hydroxides are relatively unsafe for inclusion in large amounts in a consumer product. Also, it is desirable to try to lower the amount of phosphorus contained in such compositions.